The present invention relates to an electrical connector. More specifically, the present invention relates to an electrical connector with a movable cover which transfers external force applied to the connector about the main connector body.
Electrical connectors are used in electronic devices to connect a base unit and a portable unit. A typical example is a removable car radio, which consists of a base unit installed in the car and a portable receiver unit which can be removed at night. When separated, neither unit is operable, thereby discouraging theft. When reconnected, electrical connectors in the base unit connect to circuits in the portable unit.
Referring to FIG. 7, an electrical connector according to the prior art is shown generally at 50. A connector body 52 supports a plurality of convoluted conductive contact strips 54 (only one of which is shown). Contact strips 54 are substantially parallel and separated by non-conductive portions of connector body 52. Each contact strip 54 has a first section 54a connected to a printed circuit board 70 by a solder connection 90. A second section 54s of each contact strip 54 protrudes through an opening 52a in the side of connector body 52.
For each contact strip 54, a portable unit (not shown) has a corresponding switch arm 60. Switch arm 60 has a conductive contact area 64 which selectively engages second section 54s of contact strip 54 such that the portable unit electrical connects with the base unit. An engagement means (not shown) maintains contact between contact area 64 and second section 54s.
A drawback of the above prior art is that pressure applied by switch arm 60 to contact strip 54 is usually greater than necessary to establish electrical contact between contact portion 64 and contact strip 54. For example, when pressing a button in a car radio, a user exerts several pounds of pressure in excess of that necessary to trigger the desired function. As a result, a front end of switch arm 60 transfers the excess force to connector body 52, straining the connection with circuit board 70 at solder connection 90. Over time, under the repeated stress, solder connection 90 may crack or the circuit pattern may peel off circuit board 70.
One prior art attempt to overcome this drawback uses a tilt prevention plate 80 as a buffer against external force. Tilt prevention plate 80 is usually a fixed surface within which the base unit is installed. In theory, if connector body 52 is placed flush against a solid surface, then excess force cannot move connector body 52 or otherwise strain solder connection 90. For example, in the case of a car radio, tilt prevention plate 80 could be the rear of the well in which the radio is installed.
A drawback of the above solution is that, in practice, connector body 52 cannot be installed flush against tilt prevention plate 80. Thus, even with tilt prevention plate 80, excessive force from switch arm 60 moves connector body 52 an offset distance L between connector 50 and tilt prevention plate 80. Thus, while tilt prevention plate reduces stress on solder connection 90 and prolongs the life of the connector, it fails to prevent the effects of long term use.